Strap and perforated insulator assembly



-"Ta m 5. J. GARTNER 2,956,196

STRAP AND PERFORATED INSULATOR ASSEMBLY Filed April 18, 1955 Oct. 11, 1960 INVENTOR STANLEY J. 6A RTNER ATTORNEY United States Patent STRAP AND PERFORATED INSULATOR- ASSEMBLY Stanley Jacob Gartner, Emporium, Pa., assiguor, by mesne assignments, to Sylvania Electric Products Inc., Wilmington, Del., a corporation of Delaware Filed Apr. 18,1955, Ser. No. 502,003

7 Claims. (Cl. 313-258) 1 This invention relates to insulating spacing wafer and strap assemblies such as are utilized in the construction v openings 15, 16 are generally circular. Should the rods be of other shape, the openings 15, 16 would conform thereto. The openings 15, 16, fit the rod except for. one portion of the wall of the openings here indicated as 18, The wall portion at 18 extends beyond the projected periphery of the openings 15, 16 and the space left conforms with the thickness and width of a strap or grid stop 20 as will be explained. When the strap has a rectangular cross section, the bottom of the recess is a straight line. These spaces may be placed in one only of the discs.

Cooperative with each of the openings through which a strap end is to be inserted is an opening 22. These openings 22 are spaced from the openings 15, 16, the spacings for the pairs of openings being preferably made equal to one another, so that the same sized strap could be associated with any of the pairs of openings; The openings 22 as here shown are trapezoidal in form and taper in the direction of the openings 15 and 16 and the narrowest portion of each trapezoid terminates in a straight line base portion which substantially equals the 1 width of the strap. The length of the openings 22 is by the wafer and positioned for welding to the electrode ends.

. The holes are small and the strap is of thin material of a width slightly less than the diameter of the hole. Moreover the metal is preliminarily bent into staple shape to facilitate assembly. Accurate bending of the staple and accurate registration of the staple ends and wafer holes must therefore be attained in order to effect quick assembly of parts.

g It is an object of this invention to give such form to the holes in the wafer as to make it easier to assemble parts.

It is a further object of the invention to so form the staple or strap to still further enhance the ease of strap and wafer assembly.

These and further objects will be understood in the light of the following description when taken in conjunction with the accompanying drawing in which:

Fig. 1 is a plan view of a wafer having perforations therethrough adapted to receive straps, these perforations being shaped in accordance with the invention.

Fig. 2 is a perspective view of a strap in its form preliminary to assembly with the water of Fig. 1.

Fig. 3 is a fragmental view of the wafer of Fig. l with the straps in place.

Fig. 4 is a fragmental sectional view through the wafer with a strap therein welded to a grid side rod, and

Fig. 5 is a fragmental elevational view of a mount utilizing my improved straps.

Referring to the drawings in greater detail, at 10 there is disclosed a pair of spacer discs each perforated as at 11 to receive electrode elements. In a pair of these openings is located the conventional cathode sleeve 12. The perforations are made of a size, shape and position necessitated by the electrodes utilized in the tube. In the drawing there is illustrated a mica disc perforated to receive the electrodes of a beam power tube, type 6W6, although as will be obvious, the invention is applicable to other types of tube. In the beam power tube two nested grids with aligned lateral wires are utilized, the inner grid having side rods 14 insertible through openings 15 and the outer grid having side rods insertible through openings 16.

To maintain the grid immovable, the openings 15, 16 are contoured to closely fit the side rods of the grids. In this instance the side rods are circular and so the chosen to allow for spreading of the legs 24, 26 of the straps with permissible variations in the angle ofspread of the legs.

The straps are made of pliable metal, generally U- shaped, but with one leg 24 shorter than the other leg 26 and with the legs diverging from one another. The bight 28 of the U is flat and the internal length of the bight is substantially equal to the spacing between'the' closest edges of openings 15 and 22 or of openings 16' 1 and 22. The spread of the legs, i.e., the distance between the ends of the legs 24, 26, is no greater than the distance between the most remote edges of the openings 15 and 22 or 16 and 22. Therefore, considerable latitudejn the spread of the legs is possible and yet permit of easy insertion of a strap in a pair of associated openings in the wafer. Thewidth of the straps 20 is such as to cause the straps to fit snugly in the smaller ends of the openings 22 and in the recesses 18 when the straps are thrust home through the wafers. 22 are shown as trapezoidal in form, it should be obvious that in accordance with this invention, the openings may partake of other shapes so long as the width increases in a direction away from the strap engaging edges of the openings when the strap is in home position. Likewise, the recesses 18 may partake of other shapes, but the rectangular recess 18 for the rectangular cross-sectioned strap shown gives the best results, particularly when the straps are welded to electrode components, as will be described.

The straps here shown are utilized to fasten grid side rods in place. After a strap has been inserted through a pair of wafer openings and against the upper surface of the wafer, it is bent by suitable instrumentalities so that the leg 24 projects perpendicularly to the bight portion 28 while the leg 26 is bent hard up against the under surface 30 of wafer 10, and along the leg 24. The side rod -14 of a wound grid is inserted through an opening in the wafer, as opening 15, and welding electrodes are then applied to the rod and leg 26 of the strap to weld the portions of the strap to each other and to the side rod.

Having described the invention what is claimed as new 1s:

1. A wafer and strap assembly comprising a wafer provided with an opening for the reception of the end of an electrode element, a second opening spaced from the first opening, said first opening having a recess in a wall thereof and said second opening being of variable width with the narrowest part closest to said recess in the wall of the first opening, and a strap of a width to fit snugly Although the openings" in said recess of the first opening and the narrowest part of the second opening, said strap being threaded through both of said openings with a portion overlying and in juxtaposition to one surface of the wafer, a second portion of the strap underlying and in juxtaposition to the opposite surface of the wafer, the strap also having leg portions extending at substantially a right angle to a surface of the wafer with the leg portions contacting one another.

2. In an electron tube construction, an insulating wafer with an opening therein, an electrode having a portion extending through said opening, a second opening in said wafer, said second opening being narrow where it is closest to the first opening and expanding in a direction away from said first opening, a strap passing through both of said openings of a width to fit snugly in the narrow portion of said second opening and bearing tightly against the wafer between the openings, said strap having legs extending along the electrode and fastened thereto.

3. In an electron tube construction, an insulating wafer with an opening therein, an electrode having a portion extending through said opening, a second opening in said wafer, said second opening being trapezoidal in form and narrowest where it is closest to the first opening and expanding in a direction away from said first opening, a strap passing through both of said openings of a width to fit snugly in the narrowest portions of said second opening and bearing tightly against the wafer between the openings, said strap having legs extending along the electrode and fastened thereto.

4. In an electron tube construction, an insulating wafer with an opening therein, an electrode having a portion extending through said opening, said opening being enlarged to allow space for positioning of a strap between said electrode portion and the wall of said opening, a second opening in said wafer, said second opening being narrow where it is closest to the enlargement of the first opening and expanding in a direction away from said first opening, a strap passing through the enlargement in said first opening of a width to fit snugly in the narrow portion of said second opening and through the narrow portion of said second opening and tightly engaging the girth of the wafer material between the first and second 4 openings, said strap having legs extending along the electrode and fastened to each ,other and to the electrode.

5. A wafer provided with a perforation for the reception of an end of an electrode element, a second perforation in noncommunicating relation to the first perforation and closely spaced therefrom, the wafer providing an unbroken surface between the perforations, said first perforation having a recess in a wall thereof, and said second perforation being of variable width and devoid of reentrant portion with the narrowest part closest to said recess in the wall of said first perforation and terminating in a straight line base portion.

6. A wafer provided with a perforation for the reception of an electrode element, a second perforation in noncommunicating relation to the first perforation and closely spaced therefrom, the wafer providing an unbroken surface between the perforations, said first perforation having a recess in a wall thereof, and said second perforation being in the form of a trapezoid having nonparallel sides, with the nonparallel sides tapering toward the recess in the wall of said first perforation.

7. A wafer provided with a perforation for the reception of an end of an electrode element, a second perforation in noncommunicating relation to the first perforation and closely spaced therefrom, the wafer providing an unbroken surface between the perforations, said first perforation having a recess in a wall thereof with a straight line bottom, and said second perforation being in the form of a trapezoid having a pair of parallel ends and nonparallel sides with the nonparallel sides tapering toward the recess in the wall of said first perforation and the smallest end parallel to the straight line bottom of the recess in the wall of the first perforation.

References Cited in the file of this patent UNITED STATES PATENTS 1,869,568 Krahl Aug. 2, 1932 1,870,943 Blakeman Aug. 9, 1932 2,048,257 Glauber July 21, 1936 2,075,761 Jackman Mar. 30, 1937 2,250,409 Krahl July 22, .1941 2,778,969 Gartner Jan. 22, 1957 

